Take several index cards and lay them out in front of you to start taking notes. Begin with 10 or 15 primary index cards and place the rest back so that you keep organized.
Label each of the index cards. Place sequential numbers in the upper left- or -right-hand corner of each card so the numbers are easily visible. For example, three index cards would be labeled "1," "2" and "3."
Think of broad categories or topics for each of your index cards if taking notes from a book. Write the topic name directly below the index card numbers. For example, use "Digestive," "Respiratory," "Musculoskeletal" and "Nervous System" as topic names if taking notes on the human body. Don't pre-label your index cards with topics if you are taking notes from a live lecture. Use the speaker's lecture as a guide for what labels to use on your index cards.
Write the most important concepts on your index cards corresponding to the appropriate topic. List and explain definitions, processes, and important things to remember. Write down references to page numbers in books, authors, and URLs to Internet resources.
Take additional index cards and label them with sub-topics and numbers; use these for extra note-taking space if your primary index cards are filled. For example, place the number "1-a" and the sub-topic "Organs" on a card being used for notes on the human digestive system if the "Digestive" index card is full and has no more writing space.